Example embodiments relate to an adaptive touch sensing scheme based on noise detection, and more particularly, to a touch screen sensor integrated circuit (IC) which senses a true multi-touch, a method of operating the touch screen sensor IC, and a system including the touch screen sensor IC.
Capacitive-type touch systems are widely used in mobile appliances such as a smart phone and a tablet personal computer (PC), because they provide high durability and high light transmittance and have multi-touch features and soft-touch features.
Meanwhile, capacitive-type touch systems require a variety of functions, for example, true multi-touch detection, high noise-immunity, and low power consumption.
Recently, a capacitive-type touch screen controller built in a display driver IC has been introduced in Hyoung-Rae Kim et al., “A Mobile-Display-Driver IC Embedding a Capacitive-Touch-Screen Controller System”, ISSCC Dig. Tech. Papers, pp. 114-115, February 2010.
A 1-chip solution including the display driver and the touch screen controller may reduce manufacturing costs of capacitive-type touch systems. However, the touch controller supports only a single touch or two virtual touches that use a gesture because the touch controller is based on projected capacitive touch sensing that provides an independent 1-dimensional profile for each signal of a driving line and signal of a sensing line.
In addition, because of a low signal-to-noise ratio (SNR), the touch controller may not accurately sense a touch point under strong noise environments.